B1, B2, B3, B4 Flashcards
Define movement
action by organism/part of organism causing change in position/place
Define respiration (2)
chemical reactions in cells
break down nutrient molecules and release energy for metabolism
Define sensitivity
ability to detect stimuli in internal/external and respond appropriately
Define growth
permanent increase in size/dry mass by increase in cell number/cell size (both)
Define excretion
removal of waste products from organisms
Define nutrition (3)
raw materials needed
to release energy
to make more cells for growth/development/repair
Function of cell membrane (2)
holds cell together
controls substances entering/exiting cell
Function of cytoplasm
suspends organelles
Function of nucleus (2)
control cell activities/division
stores genetic material
Function of cell wall (2)
supports cell
defines cell shape
Function of vacuole (2)
storage of some materials
support cell shape
Function of chloroplasts
photosynthesis
Features of red blood cells (3)
no nucleus
biconcave shape
haemoglobin - reacts with oxygen
Define acrosome (2)
tip of sperm cells
contains enzymes - break down egg cell membrane
Define flagellum
tail of sperm cell which powers movement
Function of cytoplasm in egg cell (2)
energy storage
nutrition for fertilised cell
Function of root hair cells
absorb water/minerals
Magnification formula
image size/actual size
Define diffusion
net movement of particles from area of high concentration to an area of low concentration down a concentration gradient and through a partially permeable membrane
Define a turgid plant cell
plant cell full of water
Define turgor pressure
pressure of water in cytoplasm against cell wall
Define osmosis
movement of water particles from one area of high water potential to an area of low water potential down a water potential gradient
Define water potential
ability of a cell to draw in water into itself
Define a plasmolysed/flaccid cell (3)
dehydrated plant cell
cytoplasm shrinks
cell membrane pulls away from cell wall
Define carbohydrates (2)
made up of simple sugars
formed from carbon, hydrogen,oxygen atoms
Define protein (2)
long chains of amino acids
formed from carbon,hydrogen, oxygen, nitrogen, (sulfur)
Define lipids (2)
made from fatty acids and glycerol
formed from carbon,hydrogen, oxygen
Test for starch (3)
iodine solution
positive - blue/black
negative - brown
Test for glucose/reducing sugars (6)
benedict’s solution
positive - orange-red
small amount - green
medium - yellow
negative - blue
must heat benedict reagent
Test for protein (3)
biuret’s reagent
positive - purple
negative - blue
Test for lipids (3)
ethanol
positive - emulsion, cloudy white solution
negative - clear
Function of biological catalyst
speed up rate of reaction
Define a substrate
molecule enzyme binds to at start of reaction
Define a product
molecule formed at end of reaction
Define complementary
enzyme active site shape matches substrate shape
Define an enzyme’s active site
space where substrate fits into enzyme
Define an enzyme substrate complex
substrate binding to enzyme
Enzymes are specific and unique
True or false
True
Effect of temperature on enzyme activity (4)
temperature increase = more kinetic energy = increase in collisions
greatest at optimum temp
greater than optimum temp = denaturation
rate of reaction decrease as enzyme active site no longer complementary to substrate
Effect of pH on enzyme activity (2)
optimum pH = rate of enzyme reaction highest
low/high pH = denaturation
Effect of substrate concentration on enzyme activity (3)
substrates increase = faster rate
gradient decreases as less active sites available
gradient plateaus = all active sites occupied
